Questions tagged [blood-pressure]
the pressure of circulating blood on the walls of blood vessels. When used without further specification, "blood pressure" usually refers to the pressure in large arteries of the systemic circulation. Use this tag in questions related to measurement and study about blood pressure and diseases which involve high/low/irregular blood pressure.
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Calculation of blood flow rate and pressure change in heart
Question: Blood flows from the left ventricle of the heart through the aortic valve and then to the aorta for system circulation. In a patient, the diameter of left ventricle outflow tract (LVOT) is ...
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Bernoulli's theorum and the circulatory system [duplicate]
I learnt that when an artery is constricted, the blood pressure in the artery increases, but if the diameter of an artery decreases, the velocity of blood through it increases (the continuity equation)...
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Do afterload and stroke volume form part of a negative feedback loop in blood pressure regulation?
Blood pressure is the product of cardiac output and total peripheral resistance:
$\text{BP} = \text{CO} \times \text{TPR}$
Since cardiac output is the product of heart rate and stroke volume, we have:
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How to understand the biophysics and math behind a 0.2 second delay between the pulse in my arm and my ankle?
I recently had a test with six blood pressure cuffs; 2 each on arms, ankles and big toes. During the test I could feel the pulses in my arms and legs, and noticed a distinct ~0.2 second delay between ...
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Why is heparin contraindicated in patients with severe uncontrolled hypertension?
Heparin is a parenteral anti coagulant- prevents clot formation by inhibiting factors 2 a and 10 a mainly. Now, patients with severe uncontrolled hypertension- have persistent bp of more than 140/90. ...
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How do physics notions of fluid dynamics relate to pressure gradients in circulation?
I'm having a hard time comprehending why sometimes physiology notions seem to contradict each other and contradict physics teachings.
More specifically I don't understand why aortic coarctation causes ...
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why dead mouse doesn't bleed when we cut their skin?
When we are pricked by a needle, we bleed nevertheless it's so small wound.
But when we do mouse anatomy, it doesn't bleed even if we cut their whole abdominal skin.
Other student asked about that, ...
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What terms or concepts are used to describe the morning metabolic phenomenon involving glucocorticoids, glucose, and blood pressure?
A recent conference report described using a vaccine-based strategy to blunt a surge of high blood pressure that occurs between 5 and 8 a.m. Apparently most heart attacks and strokes occur during ...
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Why does high blood pressure not damage the body during exercise?
Exercise is commonly understood to lower blood pressure by making the heart stronger. Mayo Clinic says,
Regular physical activity makes your heart stronger. A stronger heart can pump more blood with ...
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Why does the formula for blood velocity hold true?
v = Q/A
where
v = velocity (cm/s)
Q = blood flow (ml/s)
A = cross sectional area (cm2)
So the greater the cros sectional area, the lower the velocity, assuming that the cardiac output is a constant ...
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Will renal blood flow decrease in response to dehydration?
If dehydrated, does the correction of ECF osmolarity happen slowly enough for ECF (and therefore plasma) volume to be temporarily depleted and therefore reduce renal blood flow?
If dehydration is ...
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Consequences of abnormal blood pressure unrelated to cardiac output?
A question from Kaplan's MCAT Biology Review asks:
In bacterial sepsis (overwhelming bloodstream infection), a number of capillary beds throughout the body open simultaneously. What effect would this ...
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The blood pressure when blood comes out of body
Is there any certain amount of pressure difference between our blood pressure and barometric pressure when blood of our body begins to come out?
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Can severe vasoconstriction increase systolic blood pressure?
I know that, vasoconstriction results in increased total peripheral resistance which is responsible for the rise in diastolic blood pressure. Also, cardiac output is responsible for the systolic blood ...
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Relationship between blood pressure time series and ventricular dynamics of the heart
The answer to this question is probably very straightforward, but I have actually had some difficulty finding an explicit answer online.
To what extent does the oscillatory pattern of arterial blood ...
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Why do arteries have a small lumen? [closed]
My biology textbook says that arteries have a small lumen relative to the thickness of their walls. I understand why they need thick walls, to withstand high pressure and stretch etc. But when ...
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Edema and hydrostatic pressure
I'm currently studying Robbins basic pathology, and I'm confused about a specific statement:
It states in the book that when hydrostatic pressure is low due to a lack of albumin synthesis, it leads ...
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Osmosis and hydrostatic pressure
I'm confused about the role of hydrostatic pressure compared to osmotic pressure.
Q1:If I have a U-tube with a membrane permeable only to water molecules and equal volumes of water on either side ...
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Why is angiotensin converting enzyme localized in the lungs
I understand that it's also found elsewhere, such as in renal capillaries, but I can't see logic behind it being located in the lungs. Isn't ACE's function, through making more angiotensin II, causing ...
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Why does a stronger heart cause blood pressure go down
Intuitively, why does a stronger heart cause blood pressure to go down? The answers I've found from a cursory google search seem to indicate that it has to "work less hard" to pump the blood and that ...
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Vasoconstriction and blood flow
The resistance in a blood vessel is equal to the pressure difference divided by the blood flow. Let us now say that a sympathomimetic causes vasoconstriction which increases the resistance. Does this ...
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Cardiac cycle and atrial contraction
During atrial contraction ("a" in the figure), why does the ventricular pressure match the atrial pressure? The ventricular pressure generally stays the same throughout passive filling until it ...
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In oscillometric blood pressure measurement, why do we assume that highest oscillations correspond with mean arterial pressure?
As far as I've seen, the point on the oscillometric curve where there are greatest oscillations represents the mean arterial pressure (MAP).
My question is - why? What is the logic behind this ...
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Will being very muscular (to the point that one is characterised as obese by BMI) increase blood pressure?
It is widely accepted that obesity/overweight (which I believe refers to people with a high amount of fat cells instead of bodybuilders who weigh a lot due to lots of muscle cells) have higher blood ...
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Blood pressure in the blood vessels
Why do the capillaries have a lower blood pressure than the arteries even though the capillaries lumen is much narrower. Wouldn't the narrowness of the blood vessel increase the pressure? Also the ...
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How increased potassium intake increases sodium excretion?
"K+ antagonises the biological effects of Na+". I have been reading the same many times without any explanation. How actually (mechanism) K+ helps excretion of Na+?, their interactions? And eventually ...
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What could an increase in systolic blood pressure and decrease in diastolic mean?
Sorry if this is a really simple question but my academic background is in completely different sciences. I recently made a computer game for an experiment that was related to anxiety and relaxation. ...
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Osmotic Pressure in Capillaries [closed]
In this diagram, D is apparently the point at which "the osmotic pressure into the capillaries is the greatest", but I cannot figure out why. Any help would be much appreciated!
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Physiological Effect of Mannitol
Which Starling Force is affected by Mannitol?
I am either thinking hydrostatic pressure of interstitial fluid (because it increases interstitial fluid volume) or hydrostatic pressure of capillary (...
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How can potassium rich foods reduce blood pressure?
How come sodium increases blood pressure, but potassium, which has to some extent similar properties helps lower it?
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Is a one ventricle heart feasible?
So this is derived from a lesson at Khan Academy.
The mind activity assumes that the one ventricle heart pumps blood to the lungs for oxygenation then rest of the body. However, the problem is that ...
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High Blood Pressure - Na or NaCl? [closed]
What is the cause of high blood pressure? or, Which foods can cause high blood pressure?
Is it just sodium, or sodium chloride? I'm confused because sodium chloride should ionise in the aqueous ...
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Exsanguination Time from Damage to Major Arteries
For a game project, I need to study how much blood loss is suffered when the major arteries of the human body are severed. I believe there are medical textbooks that have collected data on blood ...
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Why do people perceive blood pressure as the force that moves the blood forwards (see details)?
For example "Veins contain a lot of valves because the blood pressure inside them is low.". This wouldn't make any sense unless if blood pressure was perceived as the force that drives the blood ...
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How are limits determined for systotic and diastotic blood pressure?
I know that the upper limits for systotic/diastotic blood pressure are 120/80. What is the mathematics behind these numbers? I am curious because I did not find information regarding how the numbers ...
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Does capillary blood pressure have any effect on how much oxygen or nutrient gets distributed to tissues?
From what I have read regarding blood pressure and blood flow, I've come to the conclusion that, apart from the osmolarity of blood, the only determinant of how much oxygen/nutrients the tissues get ...
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How does sodium ion increase blood pressure?
So I have been reading about the RAAS system and I was wondering how natrium (sodium ) ions increase blood pressure.I have been looking up on the internet and have yet to find an answer.Help
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Why is it always Sodium that we talk of in blood pressure?
Why is that we emphasize so much on sodium in blood pressure? I understand that it is a major extracellular ion, but, it also is tightly regulated. So when something is that tightly regulated, won't ...
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How does the mechanism which controls blood pressure in the brain work?
I know that pressure is sensed in the skin by mechanoreception mediated by skin receptors. Static pressure stimuli are mainly sensed by slow-adapting fibers connected to receptors like the Merkel ...
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What is the normal blood water content
What is the normal water volume per 1 L of blood, and how much deviation from that norm causes dehydration or hyponatremia?
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Is lowered blood pressure a primary lethal symptom of an opiate overdose?
When someone has a opiate overdose, they can have no or almost no pulse and can have shallow breathing or stop breathing. When you stop breathing (for example) by drowning, you can survive for a long ...
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Saturation vapor pressure effect on human body [closed]
I found this calculator:
http://www.decatur.de/javascript/dew/
It calculates the dew point based on temperature and humidity.
In the result it is mentioned the saturation vapor pressure.
I barely ...
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Why do changes in preload not cause changes in end systolic pressure?
I am trying to understand why changes in preload do not cause concomitant changes in end systolic pressure. If you have preload enhancement than this should lead to an increase in cardiac output.....
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Blood pressure measurement
When measuring your blood pressure in your arm, when you hear the sound to measure the systolic, is that sound NOT the heartbeat?
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How does pressure measured by sphygmomanometer translate directly to blood pressure?
As per my understanding a sphygmomanometer when wrapped around the arm and inflated only measures the pressure of the air inside the cuff, doesn't it? How does that translate directly to the pressure ...
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Difference between pulse and blood pressure
I'm a very naive and biologically illiterate person, and from what I've read on the internet I'm not really sure I understand the difference between pulse and ...
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Arm at Heart Level when Measuring Blood Pressure
How come that one's arm has to be at heart level so that the blood pressure can be measured accurately. I've tried researching this question, but most answers to it were just "if the arm is above the ...
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What creates the feeling of 'excess' blood pressure to an area of the body?
If I hang upside down, and feel blood rushing to my head, what structures are actually responsible for me "feeling" this excess flow of blood? Baroreceptors? Mechanoreceptors? Something else?
...
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How can heart disease cause dizziness after eating?
I have been reading several articles explaining dizziness after eating (see here and here), and both articles gloss over something that I found pretty remarkable.
Both articles claim that "heart ...
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Is the molecule nitric oxide responsible for healing blood vessels?
Is the molecule nitric oxide responsible for healing blood vessels?
How does nitric oxide heal the blood vessels?
I watched a documentary about the healing effects of nitric oxide. In the video I saw ...
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